Universal joint

ABSTRACT

An agitator comprises a main body for supporting rotatably a rotary shaft, a chuck for connecting detachably an agitating rod with the rotary shaft, starting means for starting the rotation of the rotary shaft when the chuck is covered with a chuck cover, and locking means for locking rotary shaft when the chuck is not covered with the chuck cover. The chuck cover is removed from the main body when an external force larger than a predetermined value is applied to the chuck cover. The starting means comprises a permanent magnet provided on the outer periphery of a disk hub and a magnetic sensor provided on the main body so that an output is generated to start the driving source only when the chuck cover is moved to cover the chuck. The locking means comprises a hole formed in the rotary shaft, an eccentric cam to be rotated by the chuck cover, and a lock pin which is moved by the eccentric cam so as to be inserted into the hole of the rotary shaft when the chuck is not covered with the chuck cover. A universal joint comprises a cavity formed in a joint case, a planar plate fitted in the cavity, a spherical member arranged in the cavity so that it is held by a spherical surface receiving seat and a portion of the planar plate, and pressure means for pressing the planar plate toward the spherical surface receiving seat.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This present invention relates to an agitator and a fixing device thereof, and more particularly to an agitator having a chuck and a chuck cover, and to a fixing device or a universal clamp for fixing an agitator or the like to a supporting post at an arbitrary angle.

[0003] 2. Description of the Prior Art

[0004] A conventional agitator disclosed in the Japanese Utility Model Registration No. 3010021, for example, comprises a main body of an agitator, rotary shaft, a chuck for connecting said rotary shaft with an agitating rod, and a chuck cover, wherein the chuck is covered with the chuck cover so as to prevent the hair of an operator or the like from being caught by the chuck when the chuck is rotated.

[0005] Accordingly to the conventional agitator having the cluck cover, there is no such a problem that the hair of the operator is caught by the chuck when the chuck is rotated. However, such problem cannot be solved when the chuck is not closed with the chuck cover perfectly and any device for stopping the agitator when the chuck is not closed with the chuck cover perfectly is not provided.

[0006] Further, a universal clamp for fixing physical and chemical appliances or the like to a supporting post is disclosed in the Japanese Utility Model Publication Laid-Open No. 39130/94. Such universal clamp comprises a main body, a supporting post for supporting the physical and chemical appliances, a spherical member provided on the tip end of the supporting post, a pair of holding elements for forming a spherical member supporting portion of a diameter identical substantially with or smaller than that of the spherical member, a wedge member arranged at one side of said spherical member supporting portion movably in the vertical direction, and a threaded member provided at an upper portion of said main body in order to urge said wedge member downwards to move one of said pair of holding elements toward the other of said pair of holding elements.

[0007] According to the conventional universal clamp, one of the holding elements is moved horizontally toward the other of holding elements by a horizontal component of force generated when the threaded member is rotated and thus the wedge member is moved downwards. As a result, there is such a problem that a force for holding the spherical member is small and that a large holding power cannot be obtained.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to solve the aforesaid problematic points in the prior art, and to provide an agitator and a fixing device thereof.

[0009] Another object of the present invention is to obtain an agitator comprising a rotary shaft to be rotated by a driving source, a main body for supporting rotatably the rotary shaft, an agitating rod, a chuck for connecting detachably the agitating rod with the rotary shaft, a chuck cover provided on the main body rotatably, starting means for starting the driving source when the chuck is covered with the chuck cover, and locking means for locking rotary shaft when the chuck is not covered with the chuck cover.

[0010] Further object of the present invention is to obtain the agitator, wherein the chuck cover is removed from the main body when an external force larger than a predetermined value is applied to the chuck cover.

[0011] Yet further object of the present invention is to provide the agitator, further comprising a disk hub rotatably supported by the main body, the chuck cover being connected detachably to the disk hub.

[0012] Still further object of the present invention is to provide the agitator, wherein the starting means comprises a permanent magnet provided on the outer periphery of the disk hub and a magnetic sensor provided on the main body so that an output is generated from the magnetic sensor to start the driving source only when the chuck cover is moved to cover the chuck.

[0013] Another object of the present invention is to provide the agitator, wherein the locking means comprises a hole formed in the rotary shaft, an eccentric cam to be rotated by the chuck cover, and a lock pin which is moved by the eccentric cam so as to be inserted into the hole of the rotary shaft when the chuck is not covered with the chuck cover and removed from the hole of the rotary shaft when the chuck is covered with the chuck cover.

[0014] Another object of the present invention is to provide a universal joint comprising a joint case to be mounted on a supporting post a cavity formed in the joint case, an elongated groove formed at the upper portion of the cavity, a planar plate fitted in the elongated groove, a spherical surface receiving seat for closing the cavity, a spherical member arranged in the cavity so that it is held by the seat and a portion of the planar plate deviated from the center of one surface of the planar plate toward the other side of the joint case, a ball shank, one end of which is connected to the spherical member and the other end of which is extended to the outside of the joint case and pressure means for pressing the other end of the planar plate toward the spherical surface receiving seat.

[0015] Another object of the present invention is to provide the universal joint, wherein the pressure means is a screw to be threaded in the joint case, one end of which is brought into contact with the other end on the other surface of the planar plate.

[0016] The other object of the present invention is to provide the universal joint, wherein the spherical surface receiving seat is threaded detachably in the joint case.

[0017] These and other objects and features of the present invention will become apparent from the following description in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a front view of an agitator with a chuck cover according to the present invention in a state that the chuck is covered with the chuck cover;

[0019]FIG. 2 is a side view of the agitator shown in FIG. 1;

[0020]FIG. 3 is a side view of the agitator shown in FIG. 2 without the chuck cover;

[0021]FIG. 4 is a front view of an agitator with a chuck cover according to the present invention in a state that the chuck is not covered with the chuck cover;

[0022]FIG. 5 is a side view of the agitator shown in FIG. 4 without the chuck cover;

[0023]FIG. 6 is an explanation view of a stating device of the agitator according to the present invention;

[0024]FIG. 7 is a plan view of a lock of the agitator according to the present invention;

[0025]FIG. 8 is a vertically sectional side view of a universal joint according to the present invention; and

[0026]FIG. 9 is a bottom view of a joint case with a planar plate of a universal joint according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] An embodiment of an agitator according to the present invention will now be explained with reference to the drawings.

[0028]FIG. 1 to FIG. 5 show an agitator of the present invention. Reference numeral 1 denotes a main body of the agitator, 2 denotes a rotary shaft supported rotatably by the main body 1 and driven through reduction geas by a prime mover, such as an electric motor, 3 denotes an agitating rod, 4 denotes a conventional chuck for connecting detachably said agitating rod 3 with said rotary shaft 2, 5 denotes two disk hubs supported rotatably by the main body 1 through a pivotal pin 6, 7 denotes an arcuate connecting bar for connecting outerperipheral portions of said two disk hubs 5, and 8 denotes a curved chuck cover connected to the connecting bar 7 rotatably, the chuck cover 8 being able to move between a position where the chuck 4 is covered with the chuck cover 8 and a position where the chuck 4 is not covered with the chuck cover 8.

[0029] According to the present invention, projections or holes 9 are formed at both ends of said connoting bar 7, and holes or projections 10 corresponding to the projections or holes 9, respectively, are formed at an upper inside surface of said chuck cover 8, so that said chuck cover 8 can be connected to said disk hubs 5 through said connecting bar 7 when said projections or holes 9 is brought into engagement with the holes or projections 10, respectively, and that the chuck cove 8 can be removed easily from the connecting bar 7 when an excess force is applied to said shuck cover 8 to prevent the chuck cover 8 and the disk hubs 8 from being damaged.

[0030] Further, in the present invention, a permanent magnet 11 is provided on one portion of the outer periphery of the disk hub 5 and a magnetic sensor 16 is provided on a control circuit board 17 fixed to the main body 1 in the vicinity of the outerperiphery of the disk hub 5 on which the permanent magnet 11 is provided, as shown in FIG. 6, so that an output in generated from the magnetic sensor 11 to start a motor 18 through a control circuit (not shown) only when the chuck cover 8 is moved to cover the chuck 4.

[0031] In the present invention, furthermore, as shown in FIG. 7, an elongated hole 12 extending in the axial direction of the rotary shaft 2 is formed in the rotary shaft 2, and a lock pin 13 is provided so as to move against the force of a spring 14 in a direction normal to the axial direction of the rotary shaft 2. The lock pin 13 is urged toward the rotary shaft 2 by an eccentric cam 15 fixed to the pivotal pin 6 when the chuck cover 8 is moved to a position where the chuck cover 8 does not cover the chuck 4.

[0032] According to the agitator having the above constructions of the present invention, the motor can be rotated in the state that the chuck 4 is covered with the chuck cover 8 fully, but the motor cannot be rotated if the chuck cover 8 is moved slightly from the chuck 4, because the excitation of the magnetic sensor 16 by the magnetic flux of the permanent magnet 11 mounted on the chuck cover 8 is ceased. When the cluck 4 is not covered with the chuck cover 8 fully, the lock pin 13 is urged toward the rotary shaft 2 due to the rotation of the eccentric cam 15 provided on the pivot pin 6, so that the lock pin 13 is entered into the elongated hole 12 of the rotary shaft 2 and the rotation of the rotary shaft 2 is prevented.

[0033] According to the agitator of the present invention, as stated above, such a safety gear that the motor is not started to rotation if the chuck 4 is not covered perfectly with the chuck cover 8. In other words, if the chuck cover 8 is moved slightly from the chuck 4 during the operation of the agitator the motor is stopped. When the chuck cover 8 is moved and the chuck 4 is not covered perfectly with the chuck cover 8, the lock pin 13 is inserted into the elongated hole 12 of the rotary shaft 2 and the chuck 4 cannot be rotated.

[0034] Accordingly, it is not necessary to hold by hand the rotary shaft 2 when the agitating rod 3 is replaced, and the chuck 4 can be fastened by one hand.

[0035] A universal joint of the present invention comprises, as shown in FIG. 8 and FIG. 9, a supporting post 21 extending vertically, a metal joint case 22, one end of which is fixed to the supporting post 21, a cavity 23 formed at the other end of the joint case 22, a threaded opening 24 formed at a bottom portion of the cavity 23, an elongated groove 25 of a desired depth and length formed at the upper portion of the cavity 23, a planar plate 26 of a figure similar in dimension to the figure of the elongated groove 25, to be fitted in the elongated groove 25, a disk like spherical surface receiving seat 28 threaded into the opening 24, a through hole 27 formed at the center of the seat 28, a spherical member 29 arranged in the cavity 23 so that it is held by the seat 28 and a portion of the planar plate 26 deviated from the center of the lower surface of the planar plate 26 toward the other side of the joint case 22, a ball shank 30, one end of which is connected to the spherical member 29 and the other end of which is extended to the outside of the joint case 22 passing through the through hole 27, a threaded hole 31 formed in the joint case 22 so as to communicate with one end of the elongated groove 25, and a screw 32 to be threaded into the threaded hole 31.

[0036] Reference numeral 33 denotes an elongated cutout provided in the joint case in connection with the opening 24 so that the planar plate 26 can be inserted into the elongated groove 25.

[0037] Accordingly to the universal joint of the present invention, as stated above, the spherical member 29 inserted into a space formed between the spherical surface receiving seat 28 and the lower surface of the planar plate 26 can be rotated freely in the joint case 22, so that the ball shank 30 can be arranged in an arbitrary direction with respect to the joint case 22 in a state that the screw 32 is loosened in the threaded hole 31. The planar plate 26 is inclined centering around the other end of the elongated groove 25 and the portion of the planar plate 26 deviated from the center of the lower surface of the planar plate 26 toward the other side of the joint case 22 urges strongly the top portion of the spherical member 29 downwards by the principle of the leverage, so that the spherical member 29 can be held stationarily with a pressure between the spherical surface receiving seat 28 and the planar plate 26, when the screw 32 is screwed to urge the one end of the planar plate 26.

[0038] It is desirable that the planar plate 26 and the spherical member 29 which are contacted with a large pressure with each other are made of steel and quench hardened so as to withstand the deformation and the abrasion thereof, and that the spherical surface receiving seat 28 is made of a stainless steel.

[0039] As staled above, according to the universal joint of the present invention, the joint case and the spherical surface receiving seat can be connected strongly with each other by a small force generated by the rotation of the screw, because the top portion of the spherical member is urged by the force larger than the thrust force of the screw due to the principle of the leverage, and the spherical member is urged to the entire inner peripheral surface of the spherical surface receiving seat.

[0040] While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 

What is claimed is:
 1. An agitator comprising a rotary shaft to be rotated by a driving source, a main body for supporting rotatably the rotary shaft, an agitating rod, a chuck for connecting detachably the agitating rod with the rotary shaft, a chuck cover provided on the main body rotatably, starting means for starting the driving source when the chuck is covered with the chuck cover, and locking means for locking rotary shaft when the chuck is not covered with the chuck cover.
 2. The agitator according to claim 1 wherein the chuck cover is removed from the main body when an external force larger than a predetermined value is applied to the chuck cover.
 3. The agitator according to claim 1 further comprising a disk hub rotatably supported by the main body, the chuck cover being connected detachably to the disk hub.
 4. The agitator according to claim 3 wherein the starting means comprises a permanent magnet provided on the outer periphery of the disk hub and a magnetic sensor provided on the main body so that an output is generated from the magnetic sensor to start the driving source only when the chuck cover is moved to cover the chuck.
 5. The agitator according to claim 1 wherein the locking means comprises a hole formed in the rotary shaft, an eccentric cam to be rotated by the chuck cover, and a lock pin which is moved by the eccentric cam so as to be inserted into the hole of the rotary shaft when the chuck is not covered with the chuck cover and removed from the hole of the rotary shaft when the chuck is covered with the chuck cover.
 6. A universal joint comprising a joint case to be mounted on a supporting post a cavity formed in the joint case, an elongated groove formed at the upper portion of the cavity, a planar plate fitted in the elongated groove, a spherical surface receiving seat for closing the cavity, a spherical member arranged in the cavity so that it is held by the seat and a portion of the planar plate deviated from the center of one surface of the planar plate toward the other side of the joint case, a ball shank, one end of which is connected to the spherical member and the other end of which is extended to the outside of the joint case and pressure means for pressing the other end of the planar plate toward the spherical surface receiving seat.
 7. The universal joint according to claim 6 wherein the pressure means is a screw to be threaded in the joint case, one end of which is brought into contact with the other end on the other surface of the planar plate.
 8. The universal joint according to claim 6 wherein the spherical surface receiving seat is threaded detachably in the joint case. 